I'm making a paper that proposes that the Universe is analog (unbroken, interconnected) in nature, manifesting itself as digital reality (discrete, separate from each other). But for my proposal to stand, I have to provide an example of prime analogness which I interpret as the Saguna Brahma concept of Hinduism. Fortunately or unfortunately, the Saguna Brahma concept requires a Nirguna Brahma concept which is Something non-dual/quality-less. So I support the Nirguna Bramha concept by equating it to the Tao concept of Taoism which is Something "nameless" and "only follows Itself".

Is the Buddhist "Sunya" (Void) the same as Hindu "Nirguna" and the Taoist "Tao" ? If yes, it will be consistent with Hindu and Taoist observations. If not, how does it relate to Nirguna and Saguna ?

I think you would have to be a Sanskrit expert to really conduct such an analysis. (I'm not saying that as a Sanskrit expert" although I have studied fhe language). But there are very many differences between the Advaita and Buddhist views which are practically imperceptible outside the culture in which those debates took place. So from a 'universalist' perspective, it is always possible to argue that the different formulations are 'many paths up the mountain' or variations on a theme. But the advocates for the different schools will generally object to those kinds of analogies. After all thy spent centuries debating their differences and refining them, so it won't do to say they are really 'talking about the same subject'. So I think the case is quite easy to make from the viewpoint of comparative studies, but whether that would impress any of the traditional exponents of such views,who after all are the custodians of them in some sense, is a different matter.

So my suggestion is that you could use the examples that you mentioned, but I would be very careful about conflating them. I think you need to respect their differences.

Learn to do good, refrain from evil, purify the mind ~ this is the teaching of the Buddhas

Emptiness (sunyata) in Buddhism means that things don't have a self-nature (svabhava). Emptiness is not a thing or being, it is the fact that things themselves are dependently arisen without a substance. So, it is not like Nirguna Brahman and/or the Tao at all.

"There is no such thing as the real mind. Ridding yourself of delusion: that's the real mind."(Sheng-yen: Getting the Buddha Mind, p 73)

'Nirguna', the supreme reality without form, quality, attribute) signifies in Hindu philosophy that which pervades the Universe, considered without qualities (guna), as in the Advaita school or else as without material form, as in Advaita Vedanta, it is important to note it is neither Male nor female, beyond both.Perhaps 'sunya' emptyness is a good way to describe it.

OUt of these (1) has nothing to do with Buddhism or Shramanism, (2) was heavily influenced by Buddhism, (3) again has nothing to do with Buddhism just like how Shintoism has nothing to do with Buddhism, and (4) was again heavily influenced by Buddhist Vajrayana.

So before comparing Hinduism and Buddhism, you should clearly mark the historical context along with clearly defining what you mean by "Hinduism".